During borehole-forming operations, it is necessary to make up and break down long strings of tubular goods such as drill pipe. The string of pipe may be thousands of feet long, and it is therefore necessary to transport pipe joints (approximately 33 feet in length) from a pipe rack located away from the rig up to the rig floor. The pipe is vertically supported within the derrick so that it can be connected to the pipe string located in the borehole. In coming out of the hole, the opposite sequence of events must take place.
The handling of oilwell pipe is one of the most dangerous jobs on a drilling rig. Some of the pipe weighs thousands of pounds, and it is difficult to move the pipe from a horizontal position below and away from the rig into a vertical position overlying the turntable within the rig.
Others skilled in the art have proposed various different apparatus by which pipe can be transported between a pipe rack and a rig floor, as for example, Don Beck, U.S. Pat. No. 3,713,547 issued Jan. 30, 1973, and James E. Smart, U.S. Pat. No. 3,494,483 issued Feb. 10, 1970.
It would be desirable to have made available a pipe racking apparatus which is predominantly ground supported, and which additionally is supported at the rig floor so that as the heavy pipe is transported to and from the pipe rack, there is no danger of the pipe or the pipe racking apparatus falling and injuring property and personnel. It would furthermore be desirable if the apparatus could position the pipe at an inclined location with the box end of the pipe overhanging the rig floor in ready access to the elevators. Such an apparatus is the subject of the present invention.